Defining characteristics

Robert is notable in being made out of a transparent material, allowing the viewer to see its internal workings. Besides being transparent, it also somehow has what humans would call "feelings" or "emotions", and it can become offended or confused rather easily, often resulting in it literally steaming from anger or confusion.

Behind the scenes

The character of Robert is unique in all of the history of Gerry Anderson productions in
that Gerry Anderson himself provided the voice with the aid of an artificial larynx.

Robert was also one of the most difficult marionettes to control due to its light weight.